The Arkansas City Dump sits on about 200 acres in Cowley County, Kansas. The property operated as an oil refinery and cracking plant from 1916 to 1931, was largely destroyed by fire and explosion in 1925, and then served as an unregulated dump from 1931 to 1981. It was added to the federal Superfund National Priorities List (NPL) in 1983 and has since been deleted from that list after meeting cleanup goals.
The main contaminants are sulfuric acid found in on-site sludge and residual oil products, including polycyclic aromatic hydrocarbons (PAHs), in subsurface soils. The acidic sludge was classified as hazardous under federal law because of its low pH. The PAHs in subsurface soils are not migrating and do not currently pose a threat to public health or the environment.
Cleanup was organized into separate operable units. For the North Waste Area, workers neutralized the acidic sludge and placed a soil cover over the treated material. A Declaration of Covenants and Restrictions was filed with Cowley County in 1995 to prevent any activities that could disturb the neutralized sludge or groundwater. For the oil-related contamination, the EPA determined it lacked authority under the Superfund law (CERCLA) for petroleum contaminants, so no cleanup action was selected for that unit. Construction of the primary remedy was completed in September 1992. The site was deleted from the NPL in the mid-1990s and achieved readiness for anticipated reuse in 2006. Ten businesses now operate on the site, employing 57 people and generating about $2.4 million in annual sales.
The most recent Five-Year Review, completed in June 2022, found the remedy protective of human health and the environment with no issues identified. Human exposure is under control. The city of Arkansas City maintains the site through mowing and inspections of the soil cover. Groundwater monitoring is no longer conducted because contamination has been treated to neutral pH levels and land use is restricted. The next Five-Year Review is estimated between June and August 2027.
Community members who want to stay informed can join the site mailing list for updates on future activities. Site records are available at the Arkansas City Public Library at 120 E. 5th Avenue, Arkansas City, Kansas 67005, by calling 620-442-1280. Community groups may also apply for a Technical Assistance Grant of up to $50,000 to hire their own advisor to help interpret technical reports and EPA decisions.
